The line it is referring to is saying:
————————
$(‘html, body’).animate({ scrollTop: slot.offset().top – 30 }); //sends user to form
————————

I already tried the following things:
– Turning off all other plugins
– Update the plugin
– Reinstall the plugin
– Testing on a different browsers

I also tested the plugin on a different location with the same version of WordPress (multisite) and same files that don’t work on the live server. There it works fine, so i assume something is wrong with my installation of WordPress but its kinda hard to pin point down what is going on.